The electronic structure, crystal fields, and magnetic anisotropy in RECo$_5$ magnets

TL;DR

This paper reviews methods for calculating the electronic structure and magnetic properties of RECo$_5$ magnets, highlighting new approaches for accurate magnetic anisotropy prediction and potential for high-throughput material discovery.

Contribution

It introduces a combined computational approach, including a 'penalty' functional, for improved accuracy in modeling rare-earth magnet properties.

Findings

Magnetic moments and anisotropy are obtained using multiple DFT-based methods.

The proposed methods are suitable for high-throughput screening of magnetic materials.

Introduction of a 'penalty' functional improves variational total energy calculations.

Abstract

The current progress in describing rare-earth-based magnets' electronic structure and magnetic properties is discussed. We use several currently popular electronic structure methods to show the typical values of critical parameters that define the physics of RECo$_5$ (RE = rare earth atom) materials. The magnetic moments and anisotropy of 4\textit{f} atoms are obtained using several approaches, including anisotropic 4\textit{f}-charge density-constrained DFT and DFT+HI methods. We also suggest the introduction of 'penalty' functional for obtaining correct variational total energy in the traditional Hund's rule-constrained DFT-based techniques. The applicability and future extensions are discussed. The proposed combination of methods is potentially suitable for high-throughput computational searches of new rare-earth-containing magnetic materials.